STATEN ISLAND, N.Y. -- A sweep of the borough's 287 registered sex offenders last month found nearly all of them living where they're supposed to be -- but five are missing.

Prosecutors, police and U.S. Marshals learned that four men and one woman were not at the Staten Island addresses they've listed with the state sex offender registry.

Most of the missing offenders had been charged in statutory rape incidents, where their victims were not old enough to legally consent to intercourse, according to District Attorney Daniel Donovan, whose office oversaw the sweep. And one of the five may not have committed a sexually-motivated crime, though the charge against her, unlawful imprisonment of a child, by state law is a registerable offense.

No level three offender -- deemed a high risk of repeat offense and a threat to public safety -- is unaccounted for.

"I don't think the public has any reason to be afraid, they should just be aware," Donovan said. "They were not stranger-on-stranger crimes."

The sweep, which was dubbed "Operation Island Storm" and took place between March 21 and 31, involved 20 U.S. Marshals and NYPD officers.

The state's sex offender registry was created in 1996 as a result of Megan's Law, which was adopted in various forms nationwide and named for Megan Kanka, 7, a New Jersey girl killed in 1994 by a neighbor who was a convicted pedophile.

"We thought we'd take an aggressive approach, rather than waiting for people to be found out of compliance," Donovan said.

The borough's compliance rate for sex offender registration stands at 96 percent, with just nine offenders flouting the law and not informing authorities of their location.

That's a lot higher than authorities typically see, said Charles G. Dunne, the U.S. Marshal for the Eastern District of New York.

"Across the country, it hovers around 80 (percent,)" he said, attributing the high number to the work done by the NYPD's Sex Offender Monitoring Unit. "They're on the ball."

Laura Ahearn, the executive director of the non-profit Parents for Megan's Law and the Crime Victims Center, echoed that sentiment, saying that a 2003 study showed the compliance rate at 76 percent.

"That's very impressive," she said of Staten Island's rate. "What it is is an indication of the police's proactive enforcement of the law."

Paul Browne, the NYPD's deputy commissioner for public information, said the police have done similar sweeps in the city's public housing developments in the past.

"One out of compliance is one too many," Browne said, adding, though, that he considered a 96 percent compliance rate a success.

Four of the nine have been arrested -- three on charges of failing to register as a sex offender, a class E felony punishable by one-and-a-third to four years in prison, the fourth under the federal Adam Walsh Act, after he moved to Alabama and failed to register with law enforcement officials there.

Two of the sex offenders on the registry were dead, one had been deported, three have moved out of state and have let law enforcement officials at their new homes know of their whereabouts, and six are locked up on unrelated charges, officials said.

"We found nine people not in compliance. That's nine too many for me. Four of those people are facing the consequences of not being in compliance, and five more will, once we get our hands on them," Donovan said.

The missing sex offenders include:

-- Jamel Jackson, 26, a level two offender convicted of sexual misconduct in 2009, after having sex with a 15-year-old female acquaintance. Jackson, who did not use force, authorities said, was sentenced to seven months in jail. His last address is listed as 181 Gordon St., Apt. 3A in Stapleton.

-- Tywann Johnson, 24, a level two offender convicted of sexual misconduct in 2006, after being arrested in Gloversville, N.Y. and accused of having sex with a 15-year-old acquaintance. Johnson did not use force, public records show, and was sentenced to time served and 6 years probation. His last known address was on Staten Island, in a basement apartment at 26 Jake St. in Stapleton.

-- Carnell McCarden, 51, a level two offender who was convicted in 1999 of third-degree rape. Public records say McCarden repeatedly had sex with a 15-year-old girl, and established a relationship with the girl to groom her for victimization. He was sentenced to nine months in jail. McCarden, who also goes by the first name, Goldie, was last known to live at 35 York Ave., Apt. 3, in New Brighton.

-- Beverly Astwood, 43, a level one offender who was required to register after an unlawful imprisonment conviction, though the charges against her did not include a sexual element. On Oct. 23, 2000, Ms. Astwood was supposed to be baby-sitting a 1-year-old in a van parked outside Stapleton Criminal Court while the mother was inside, except she drove off before the mother came back.

A 10-hour manhunt ensued, and police found her, the car, and the child at the corner of Jersey Street and Brighton Avenue at 1 a.m. the next day. She admitted she had smoked crack in front of the boy. Ms. Astwood ultimately pleaded guilty to first-degree unlawful imprisonment. Her last known address was 110 North Burgher Ave. in West Brighton.

-- Jermaine Scott, 29, a level one offender convicted of third-degree rape in 2004. He was 19 at the time of his September 2003 arrest, and his victim was younger than 15, according to prosecutors. Scott spent an unspecified time in jail, then a year and 8 months in state prison after violating the terms of his release, prosecutors said.

None of the five have warrants out for their arrest, though authorities are seeking them as Megan's Law violators.

"They're in violation right now. We have deemed them to be in violation," Donovan said. "We spoke to neighbors, we spoke to new tenants."

Anyone with information about their whereabouts is asked to call the 24-hour tip line at Donovan's office, (718) 556-7030.